A box has 12 tickets numbered 1 to 12. One is picked at random. What is the probability that its number is a multiple of 3?
Answer and explanation
Correct answer: B. 1/3
- Step 1: The multiples of 3 up to 12 are 3, 6, 9, 12. Step 2. There are 4 of them out of 12 tickets: probability = 1/3. Answer: 1/3. Why not the others: 1/12: That counts only one ticket instead of every multiple. 1/4: That uses the divisor as the number of favourable tickets. 5/12: That counts one multiple too many.
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